What the ratings mean for fit
The Siemens 3VA2225-8HL32-0CH0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current (Iu) at 40 °C, with an ETU320 electronic trip unit for line protection. The interrupting ratings are 440 kA at 240 V and 330 kA at 415 V — figures that govern fault-clearing capability in high-fault-current distribution panels. The 800 V rated insulation voltage (Ui) sets the maximum system voltage the breaker can be applied to without dielectric breakdown.
Thermal derating and enclosure integration
The 250 A rating holds flat from 40 °C through 50 °C, then derates to 241 A at 55 °C and 213 A at 70 °C. In a sealed panel with limited airflow, the 70 °C ceiling means the breaker must be loaded to 213 A or less to stay within the thermal curve. The 86 mm depth and 105 mm width fit standard SENTRON 3VA2 panel cutouts; the 181 mm height leaves clearance for the undervoltage release (UVR) module on the left side. Power dissipation peaks at 50.5 W — account for that heat in the enclosure's thermal budget.
Trip unit and auxiliary configuration
The ETU320 electronic trip unit provides LI (long-time and instantaneous) protection with adjustable settings. An undervoltage release (UVR) is factory-installed, and the auxiliary contact block carries 2 auxiliary switches plus 1 trip alarm switch (HQ). The breaker includes a mechanical trip indicator for visual fault confirmation. No communication function, phase failure detection, or ground fault monitoring is fitted on this variant.